Data from: Species limits and introgression in Pimelodus from the Magdalena-Cauca River basin

Low morphological differentiation among taxa hampers its appropriate
identification, basic biological studies, and promotion of any
conservation effort. Aiming to clarify the evolution and speciation among
members of Pimelodus from the Magdalena-Cauca River basin, this study
tested the hypothesis that P. yuma, P. grosskopfii and P. crypticus
represent three independently evolving species and explored signals of
interspecific hybridization. Likewise, we test the ancient hypothesis that
the trans-Andean Pimelodus yuma and P. crypticus belong to the cis-Andean
P. blochii species complex. The outcomes based on mitochondrial (cox1) and
nuclear [RADseq (Illumina Hi-Seq), microsatellites and rag2] markers
combined with coalescence-based and allele-frequency methods, confirm that
each studied trans-Andean species represent an independently evolving
unit. We used Stacks v.2.52 for de novo SNP genotyping. Contrary to
expectations, P. yuma was found as a sister clade of P. blochii, while P.
crypticus (confused for a long time with P. blochii) was phylogenetic
closer to P. grosskopfii. Additionally, we found strong evidence of
historical introgression between the non-sibling species Pimelodus yuma
and P. grosskopfii, breaking the absence of interbreeding and the
independent evolutionary trajectory among Trans-Andean Pimelodus during
their diversification history, a pre-requisite to define species limits.
However, non-significant values of current gene flow were evidenced
between them, supporting the hypothesis of full isolation.